<!DOCTYPE html>
<html lang="zh-cn">
<head>
	<meta charset="utf-8">
	<title>011-类选择器.html</title>
	<style>
		.teach{
			color: blue;
		}
		.student{
			color: red;
		}
	</style>
</head>
<body>
	<p class="teach">mr1</p>
	<p class="teach">mr2</p>

	<p class="student">ci1</p>
	<p class="student">ci2</p>
</body>
</html>